1. Field of the Invention.
The present invention relates generally to an alternate recharge and discharge rotary valve for use in a piston pump assembly to discharge a metered amount of liquid, gel, or slurry, and particularly a rotary valve having a first channel pathway segregated from a second fluid pathway, the first channel pathway providing a metered amount of liquid, gel, or slurry to a piston bore pathway and the second channel pathway providing an exit to dispense the same. The present invention is particularly useful to dispense gel or slurry used in battery fills, however, it is understood that the invention is not limited to this particular application.
2. Description of the Related Art.
A variety of metering piston pumps are used in many environments were a precisely measured quantity of a liquid is required to be dispensed. Examples of such applications are in the packaging of liquid medicaments and perfumes. A typical metering pump for this purpose employs a reciprocating plunger to draw a charge of liquid into a cylinder and then expelled the charge from the pump at each reciprocation of the plunger. The liquid enters and leaves the cylinder through the same port, and a rotary valve is provided to place the port, alternatively, in communication with the supply of liquid and an outlet from the pump. However both entry and exit of the metered liquid into a cylinder from the same port can be disadvantageous, particularly in a number of metering piston pump applications involving dense liquids, gel, or slurries. In such applications the consistency of the dispensed liquid, gel or slurry can vary, contain contaminants, form lump-like portions, or develop cling sediment, thereby causing problems of restricted or clogged entry or dispensing pathways.
In accordance with the present invention there is provided a rotary valve for use in a piston pump assembly to discharge a metered amount of liquid, gel, or slurry comprising a valve body having a first channel pathway and a second channel pathway. The first channel pathway has an inlet opening to receive a liquid, gel, or slurry and an outlet opening to provide the liquid, gel, or slurry to a pathway of the piston pump assembly. The second channel pathway has a plurality of inlet openings each capable of communicative alignment with the pathway of the piston pump assembly and at least one outlet opening communicative with said inlet openings. Preferably the second channel pathway is generally X-shaped, having an upper distal side opening and an upper proximal side opening at an upper portion thereof and a lower distal side opening and a lower proximal side opening at a lower portion thereof. The valve body is capable of rotation with respect to the piston pump assembly to dispose the inlet opening of the first channel pathway to both an operative position to receive the liquid, gel, or slurry through the inlet opening of the first channel pathway and provide the same to the outlet opening of the first channel pathway, and an inoperative position closing the first channel pathway from fluid communication with the liquid, gel, or slurry. The valve body is further capable of rotation with respect to the piston pump assembly to separately dispose the second channel pathway to an operative position to discharge the liquid, gel, or slurry from the piston pump assembly and an inoperative position to prevent the discharge. The present invention also encompasses a piston pump rotary valve assembly for use in discharging a metered amount of liquid, gel or slurry and also such an assembly, and preferably a plurality of such assemblies in combination with a tank dispenser.
The present invention advantageously provides for a fill or recharge cycle of a metered amount of liquid, gel or slurry from the first channel pathway of the rotary valve to a piston pump pathway which is distinct, divided, and separated from a discharge cycle wherein the liquid, gel or slurry is discharged from the piston pump pathway. Further, the present invention advantageously allows for a four cycle location rotation of the rotary valve at each quarter turn thereof relative to the piston pump pathway which establishes an xe2x80x9calternate recharge and dischargexe2x80x9d, and xe2x80x9cfresh-in, fresh-outxe2x80x9d mode of operation for the subject liquid, gel or slurry in the piston pump pathway. Such a four cycle location of the rotary valve provides for a piston pump pathway fill to discharge to fill to discharge sequence relative to the piston pump assembly. Moreover, by exhausting all liquid, gel or slurry from the piston pump pathway during discharge cycles, fresh liquid, gel, or slurry is always provided during fill cycles of the piston pump pathway. Still further, the rotary valve of the present invention importantly has an end portion which rotatably functions as an impeller to stir liquid, gel, or slurry within an impeller displacement zone thereby breaking up clumps, sediment, impurities, or lack of consistency in the liquid, gel, or slurry just prior to entry of the same to the first channel pathway of the rotary valve which supplies the liquid, gel, or slurry to the piston pump pathway. Such advantages allow the rotary valve, the rotary valve assembly, and the rotary valve assembly tank dispenser of present invention to be used with caustic gels or slurries which contain contaminants, form lump-like portions, or otherwise feature variations in their consistency while limiting or altogether eliminating development of cling sediment which can cause serious problems of restricted or clogged piston pump or rotary valve entry or dispensing pathways necessitating maintenance and repair and associated system downtime.
Additional features and advantages of the present invention will become apparent to those skilled in the art from the following description and the accompanying figures illustrating preferred embodiments of the invention, the same being the present best mode for carrying out the invention.